How a Chinese 'spy balloon' prompted the U.S. to scour the skies

In this image released by the U.S. Navy, sailors assigned to Assault Craft Unit 4 prepare material recovered off the coast of Myrtle Beach, S.C., in the Atlantic Ocean from the shooting down of a Chinese high-altitude balloon, for transport to the FBI, at Joint Expeditionary Base Little Creek in Virginia Beach, Va., on Feb. 10. (Ryan Seelbach/U.S. Navy/via AP)

A trade war, semiconductors, human rights: in recent years, the U.S.-China relationship has been rocked by successive geopolitical crises that have strained the dynamic between two of the world's most powerful countries.

Now a balloon is threatening to derail any possibility of a diplomatic détente, with Beijing also accusing the U.S. of sending balloons to China.